Refs #29724 -- Added is_dst parameter to QuerySet.datetimes().

Thanks Simon Charette for the review and Mariusz Felisiak for tests.

django/db/models/query.py

@@ -875,7 +875,7 @@ class QuerySet:
             'datefield', flat=True
         ).distinct().filter(plain_field__isnull=False).order_by(('-' if order == 'DESC' else '') + 'datefield')
 
-    def datetimes(self, field_name, kind, order='ASC', tzinfo=None):
+    def datetimes(self, field_name, kind, order='ASC', tzinfo=None, is_dst=None):
         """
         Return a list of datetime objects representing all available
         datetimes for the given field_name, scoped to 'kind'.
@@ -890,7 +890,13 @@ class QuerySet:
         else:
             tzinfo = None
         return self.annotate(
-            datetimefield=Trunc(field_name, kind, output_field=DateTimeField(), tzinfo=tzinfo),
+            datetimefield=Trunc(
+                field_name,
+                kind,
+                output_field=DateTimeField(),
+                tzinfo=tzinfo,
+                is_dst=is_dst,
+            ),
             plain_field=F(field_name)
         ).values_list(
             'datetimefield', flat=True